Luminous discharge lamp



April 24, 1934. M, E, MUSE 1,955,971

LUMINOUS DI SCI-IARGE LAMP Filed March 29. 1932 2 Sheets-Sheet l INVENTOR ATTORNEYS April 24, 1934. M. E. MUSE 1,955,971

LUMINOUS DISCHARGE LAMP Filed March 29, 1952 2 Sheets-Sheet 2 HINGE)? a" ZGWTQ' ATTORNEY;

Patented Apr. 24, 1934 PATENT OFFICE 1,955,971 LUMINOUS DISCHARGE LAMP Melvin Edward Muse, Richmond, Va., assignor to William Floyd Lee Application March 29, 1932, Serial No. 601,756

21 Claims.

This invention relates to the art of illumination and particularly to that branch of the art which deals with luminous discharge lamps.

Much consideration has been given to the problem of providing special illumination for the dial of an automatic telephone so that it can be seen distinctly no matter where the telephone might be located. Various types of lamps have been proposed for this purpose, but so far as I am aware, none 'has had practical application because no one has yet devised a lamp which answers all of the requirements. These requirements are both physical and electrical. From the physical standpoint, the shape and size of the lamp must be such that it can be positioned where it will not be in the way to the least extent sothat there can be no possible objection to its presence. From the electrical standpoint, it should be a low voltage lamp and thus capable of operation from the standard 24 volt telephone circuit; and yet it should be capable of withstanding the electrical surges which take place during dialing and which sometimes increase the voltage to as much as 800 volts or more.

I havev provided a lamp which answers all of these requirements. It is of the luminous discharge type and can be given such physical characteristics that it can be combined with the 'dial structure of the telephone so as to properly illuminate it and yet its presence is hardly noticeable. Notwithstanding the fact that it is of the luminous discharge type the lamp is capable of operating at a voltage as low as 24 volts, and

can therefore be connected directly to the telephone circuit. Moreover, it is capable of withstanding the large increases in voltage which take place during dialing.

The lamp itself will first be described and then the manner in which it may be associated with the telephone dial and electrically connected in the telephone circuit will be explained.

In the accompanying drawings:

Figure l is a horizontal section of a lamp embodying the invention.

Fig. 2 is a horizontal section of a modified form of the lamp.

Fig. 3 is a transverse section taken on theline 3-3 of Fig. l.

Fig. 4 illustrates how several lamps of the type shown in Fig. 2 may be connected in multiple, each lamp being represented in horizontal section.

Fig. 5 is a horizontal section of a lamp of the kind shown in Fig. 2, but which has been given a ring-like shape to adapt it for use in combination with a telephone dial.

Fig. 6 isa transverse section taken on 66 of Fig. 5.

Fig. 7 is a diagrammatic view showing how the lamp may be connected in the telephone circuit.

Fig. 8 is a vertical section of the dial mechanism of a telephone showing the lamp associated therewith.

Fig. 9 is a horizontal section taken on the line 9-9 of Fig. 8.

Fig. 10 is a vertical section through the dial mechanism of a telephone illustrating another way in which the lamp may be associated therewith; and

Fig. 11 is a horizontal section taken on the line 11--11 of Fig. 10.

Referring first to Figs. 1 and 3, the lamp comprisesa tube 1 made of glass or other transparent material. It contains three electrodes, 2, 3, and 4, suitably supported within the tube and held in spaced relation as by means of the supports 5 and 6 made of glass or the like. The electrodes may be made of nichrome, tungsten, silver, or any other suitable material. The electrodes 2 and 4 are electrically connected by lead-in wires '7 and 8 to the same side 9 of an external circuit. The electrode 4 is connected in series with a high resistance 10. When the lamp is connected to a telephone circuit this resistance should be of the order of 100,000 ohms. The remaining electrode 3 is connected by means of a lead-in wire 11 to the other side 12 of the external circuit. The leadin wires 7, 8, and 11 are sealed in the glass tube as represented in the drawings. Located within the tube against its wall is a deflector 13 which is electrically connected with the electrode 3 as represented at 14. The deflector may be made of chromium, silver, or any other material which is a conductor of electricity and which is capable of receiving a high polish. The deflector may be formed of thin metal or may be electrically deposited on the glass.

The tube is filled with helium, neon, or mercury vapor, or any mixture of these gases. Preferably, it contains all three of the gases in combination. A mixture of the three gases has been found especially suitable where the lamp is to operate at low voltages. The helium gas is believed to be the principal one. The others may be added as desired to suit specialconditions. If the neon is omitted altogether, the lamp will give a white light and can be operated at about 110 volts, but for a very low voltage lamp the use the line of neon is advisable because it, when used with the other gases still further reduces the required voltage and the current consumption.

The electrode 4 is preferably coated with a radioactive substance such as thorium or cerium oxide. The electrodes 2 and 3 may likewise be coated if so desired.

As the electrodes 2 and 4, which are connected in parallel to the lead-in wire 9, are closer to the electron-deflecting electrode '13 than to the electrode 3, which'is connected to the lead-in wire 12, ionization of the gases in casing 1 will take place between one 'or both of the electrodes 2 and 4 and the electron-deflecting electrode 13 before ionization of gases takes place between the electrode 3 and either electrode 2 or 4. If the electrode 4 alone is coated with thorium it would initiate ionization, as such a coating renders the electrode more efiective for that purpose, especially at low voltages, and also causes the glow to be continuous. The deflector 13 materially aids in the ionization of the gas by deflecting the electric charges back to the interior of the tube. It also serves as a reflector of the light. The deflector should be as long as possible from the electrical and light-reflecting point of view, but as short as necessary to obtain the desired amount of direct illumination.

The lamp shown in Figure 2 is structurally the same as that shown in Figure 1, but the circuit connections are difierent. In Figure 2, the electrode 2 is connected to the external lead 12, and the electrodes 3 and 4 are connected to the external lead 9. In this case, the electrode 3 is the starting electrode and is connected in series with the resistance 10. The electrode 4, in this case, is the one which is electrically connected to the deflector 13. At the present time, I prefer the circuit arrangement shown in this figure.

Figure 4 shows several lamps connected in multiple, the circuit connections being the same as shown in Figure 2.

The tube of the lamp may be made in the shape of a ring as'shown at 15 in Figure 5. The lamp is preferably given this shape when it is to be associated with the dial of an automatic telephone in the manner hereinafter described. The electrodes in this case are likewise given a ring shape as represented at 2, 3, and 4'. The deflector, corresponding to the deflector, 13 in Figures 1 and 2, is represented at 13' and is so located within the tube that it will reflect the light radially outward.

The way inwhich a lamp of the kind shown in Figure 5 may be associated with the dial of an automatic telephone is shown in Figures 8 and 9.

The number plate of the dial is represented at 16.-

It is usually held in place by the edge of a clamping disc 17. I modify this disc to the extent of elevating it slightly and also extending it radially a suflicient distance for it to act as a shield for the lamp which is positioned just under its marginal edge. The light reflected outwardly by the reflector 13' thus shines directly on the number plate 16. The usual finger disc which rotates above the number plate is represented at 18.

In Figures 10 and 11, the lamp is located under the number plate. In this case, the numbers and letters are cut out of the number plate so that the light from the lamp may shine through them. The lamp tube is represented at 20 and is somewhat flattened. A ring 21 preferably made of fibre elevates the number plate 16' so that it can be located above the lamp. The vertical dimensions of other parts of the dial-mechanism m y be increased wherever necessary to bring the rotatable finger disc 18 in its proper relation above the number plate.

The lamp may be connected across the telephone line, in which case it will be constantly illuminated, or it may be connected so that it will be illuminated only when the telephone receiver is of! the hook. Figure 'I shows a circuit arrangement which will accomplish this. When the telephone receiver 22 is on the hook 23 the supply of current to the lamp will be interrupted, but when the receiver is removed from the hook, the necessary connections are established to supply current to the lamp and cause it to illuminate the dial.

It will now be seen that from the physical standpoint, the lamp is well adapted for use in combination with a telephone dial. From the .electrical standpoint, it is also well adapted for this use because it is capable of operating at a voltage as low as 24 volts. It will also stand much higher voltages such as occur during dialing.

While my lamp is particularly adapted for use in connection with a telephone dial, and in that relation provides a combination which is believed to be the first practical one of its kind, nevertheless, it is capable of other uses. Because of its ability to withstand such a large range of voltages, it is particularly useful on circuits of undetermined voltages. The lamp is also capable of operating at low frequency. This is very desirable in sign work because the tube may be made very short, and each letter may be lighted separately and replaced separately in case of breakage.

The improved lamp may be used for night clocks, for traflic signals, and in other relations where its particular characteristics render it serviceable.

I claim:

1.'A luminous discharge lamp comprising a casing, at least three discharge electrodes in the casing two of which are connected in parallel, at least one of said electrodes being coated with a radio-active substance, and a gaseous atmosphere in the casing.

2. A luminous discharge lamp comprising a casing, at least three electrodes in the casing, at least one of said electrodes being coated with a radio-active substance, a gaseous atmosphere in the casing, and a deflector located against and covering a. part only of the wall of said casing and electrically connected with one of the electrodes.

3. A luminous discharge lamp comprising a casing, at least three electrodes in the casing, a gaseous atmosphere in the casing, and a deflector located against and covering a part only of the wall of said casing and electrically connected with one of the electrodes.

4. A luminous discharge lamp in accordance with claim 2, in which the gaseous atmosphere in the casing comprises a mixture of helium, neon and mercury vapor.

5. A luminous discharge lamp in accordance with claim 3, in which the gaseous atmosphere in the casing comprises a mixture of helium, neon and mercury vapor.

6. A luminous discharge lamp comprising a casing, at least three discharge electrodes in the casing, at least one of said electrodes being coated with a radio-active substance, a gaseous atmosphere in the casing and an electron deflector extending from one side of the casing.

Lil

7. A luminous discharge lamp comprising a casing, at least three discharge electrodes in the casing, a gaseous atmosphere in the casing and an electron deflector extending from one side of the casing. I

8. A luminous discharge lamp comprising a casing, at least three electrodes in the casing, a gaseous atmosphere in the casing comprising a mixture of helium, neon and mercury vapor and a deflector in the casing electrically connected with one of the electrodes.

9. A luminous discharge lamp comprising a casing, at least three electrodes in the casing, at least one of said electrodes being coated with a radio-active substance, a gaseous atmosphere in the casing comprising a mixture of helium, neon and mercury vapor, and a deflector in the casing electrically connected with one of the electrodes.

10. A luminous discharge lamp comprising an elongated casing filled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having a substantial surface area formed on a portion of the inside of said casing, and a second electrode extending longitudinally through said casing.

11. A luminous discharge lamp comprising an elongated casing filled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having substantial surface area formed on a portion of the inside of said casing, and a second electrode extending longitudinally through said casing, said second electrode being sufliciently close to said first electrode to set up an initial ionization of gases between said electrodes when an electric-current is passed therethrough.

12. A luminous discharge lamp comprising an elongated casing filled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having a substantial surface area formed on the inside of said casing at one end thereof, and a second electrode extending longitudinally through said casing, said electron-deflecting electrode at least partially enclosing a portion of the gases in the casing, whereby when an electric current is passed through said electrodes the concentration of ionized electrons in the portion of the gases at least partially enclosed by said electrondefiecting electrode occurs.

13. A luminous discharge lamp comprising a casing, said casing having an atmosphere including mercury vapor and at least one ionizable gas, an electron-deflecting electrode having a substantial surface area in said casing, and a second electrode in said casing, said electron-deflecting electrode at least partially enclosing a portion of the atmosphere in the casing, whereby when an electric current is passed through said electrodes a concentration of mercury ions occurs in that portion of the atmosphere which is at least partially enclosed by said electron-deflecting electrode, with a resulting concentration of the ionizable gas in the other portions of the casing.

14. A luminous discharge lamp comprising a casing, said casinghaving an atmosphere including mercury vapor and at least one ionizable gas, an electron-deflecting electrode having a substantial surface area in said casing, at least three other electrodes in said casing, one of said other electrodes being electrically connected in parallel to the electron-deflecting electrode, said electrondeflecting electrode at least partially enclosing a portion of the atmosphere in the casing, whereby when an electric current is passed through said electrodes a concentration of mercury ions occurs in that portion of the atmosphere at least partially enclosed by said electron-deflecting electrode with a resulting concentration of the ionizable gas in the other portions of the casing.

15. A luminous discharge lamp comprising a generally tubular casing filled with a gaseous atmosphere capable of being ionized, a plurality of electrodes extending longitudinally of said casing, said electrodes being substantially co-extensive longitudinally, and an electron-deflector extending from one end of said casing.

16. A luminous discharge lamp comprising a generally tubular casing filled with a gaseous atmosphere capable of being ionized, a plurality of electrodes extending longitudinally of said casing, said electrodes being substantially co-extensive longitudinally, and an electron deflector having a substantial surface area formed on the portion of the inside of said casing and extending longitudinally thereof from one end.

1'7. A luminous discharge lamp, comprising a casing filled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having substantial surface area, at least three other electrodes in said casing, lead-in wires to which said electrodes are connected, one of said electrodes connected to one lead-in wire being closer to said electron-deflecting electrode than to an electrode connected to the other lead-in wire, whereby when electric current is passed through said electrodes ionization of gases takes place between the electron-deflecting electrode and one of saidother electrodes before ionization of gases takes place between the other electrodes.

18. A luminous discharge lamp, comprising a casing filled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having a substantial surface area, at least three other electrodes in said casing, lead-in wires to which said electrodes are connected, two of said other electrodes being electrically connected in parallel, and one of said other electrodes connected to one lead-in wire being closer to said electron-deflecting electrode than to an electrode connected to the other lead-in wire, whereby when an electric current is passed through said electrodes ionization of gases takes place between the electron-deflecting electrode and one of the said other electrodes before ionization of gases takes place between the other electrodes.

19. A luminous discharge lamp, comprising a casing filled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having a substantial surface area, at least three other electrodes in said casing, lead-in wires to which said electrodes are connected, one of said other electrodes connected to one lead-in wire being closer to said electron-deflecting electrode than to an electrode connected to the other leadin wire, whereby when an electric current is passed through said electrodes ionization of gases takes place between the electron-deflecting electrode and one of said other electrodes before ionization of gases takes place between the other electrodes, the electrode closest to said electrondefiecting electrode and one of the other of said electrodes being electrically connected in parallel, and a resistance in the line leading to the electrode closest to the electron-deflecting electrode.

20. A luminous discharge lamp, comprising a casingfilled with a gaseous atmosphere capable of being ionized, an electron-deflecting electrode having substantial surface area, and at least three other electrodes in said casing, lead-in wires to which said electrodes are connected, one of said other electrodes connected to one lead-in wire being closer to said electron-deflecting electrode than to an electrode connected to the other leadin wire, whereby when an electric current is passed through said electrodes ionization of gases takes place between the electron-deflecting electrode and one of said other electrodes before ionization of gases takes place between the other electrodes, one of the electrodes remoter from the V which said electrodes are connected, one of said other electrodes connected to one lead-in wire being closer to said electron-deflecting electrode than to an electrode connected to the other leadin wire, whereby when electric current is passed through said electrodes ionization of the atmosphere takes place between the electron-deflecting electrode and one of said other electrodes before ionization of the atmosphere takes place between the other electrodes, one o! the electrodes remoter from the electron-deflecting electrode being electrically conected in parallel 'to the electrode closest said electron-deflecting electrode, said electron-deflecting electrode at least partially enclosing a portion of the atmosphere in the cas- MELVIN EDWARD MUSE. 

